Composition for providing an abrasion resistant coating on a substrate with a matched refractive index and controlled tintability

ABSTRACT

The present invention discloses articles containing a coating composition, as well as methods of making and using the compositions which, when applied to a substrate and cured, provide articles having transparent abrasion resistant coatings, wherein the coatings have a matched refractive index to that of the substrate and can be tailored to control the extent of tint absorption (vide infra). The coating compositions comprise an aqueous-organic solvent mixture containing a mixture of hydrolysis products and partial condensates of an epoxy-functional silane, a carboxylic acid functional compound selected from the group consisting of carboxylic acids, multifunctional carboxylic acids, anhydrides, and combinations thereof, a metal oxide composite colloid, and a disilane. The coating compositions may further include a mixture of hydrolysis products and partial condensates of one or more silane additives, a colloidal silica material, and a tetrafunctional silane.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of copending U.S. patent application Ser. No.09/938,039, filed Aug. 23, 2001, entitled an COMPOSITION FOR PROVIDINGAN ABRASION RESISTANT COATING ON A SUBSTRATE WITH A MATCHED REFRACTIVEINDEX AND CONTROLLED TINTABILITY, which is a continuation of U.S. Ser.No. 09/553,583, filed Apr. 20, 2000, entitled COMPOSITION FOR PROVIDINGAN ABRASION RESISTANT COATING ON A SUBSTRATE WITH A MATCHED REFRACTIVEINDEX AND CONTROLLED TINTABILITY, now U.S. Pat. No. 6,342,097 whichclaims priority und 35 U.S.C. § 119(e) of U.S. Provisional Ser. No.60/130,767 filed Apr. 23, 1999, entitled COMPOSITION FOR PROVIDING ANABRASION RESISTANT COATING ON A SUBSTRATE WITH A MATCHED REFRACTIVEINDEX AND CONTROLLED TINTABILITY, the contents of which are herebyexpressly incorporated in their entirety by reference

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to coating compositions as well as methodsof making and using same, and more particularly but not by way oflimitation, to coating compositions which, when cured, providesubstantially transparent coatings having abrasion resistance, a matchedrefractive index to that of the substrate, and which can be tailored tocontrol the extent of tint absorption.

The present invention also relates to liquid coating compositions aswell as methods of making and using same having improved abrasionresistance and improved stability wherein the liquid coatingcompositions are derived from aqueous-organic solvent mixturescontaining effective amounts of an epoxy-functional silane, a carboxylicacid component, a colloidal metal oxide component, and a disilane.

2. Description of Prior Art

Silica based coatings deposited on plastic materials are useful fortheir abrasion resistance and weatherability and thus extend the useablelife of the plastic material. These coatings, in most cases, do notmatch the refractive index of the plastic material and allow forinterference patterns to arise due to the refractive index mismatchbetween the cured coating film and the plastic substrate material. Thismismatch leads to increased reflectivity of the coated plastic materialand to exacerbation of material flaws due to the increased reflectivity.

BRIEF SUMMARY OF THE INVENTION

The present invention provides compositions and methods of using andmaking said compositions, having improved stability which, when appliedto a variety of substrates and cured, form transparent coatings whichhave abrasion resistant properties, a matched refractive index to thatof the substrate, and which can be tailored to control the extent oftint absorption.

Broadly, the coating compositions of the present invention comprise anaqueous-organic solvent mixture containing from about 10 to about 90weight percent, based on the total solids of the composition, of amixture of hydrolysis products and partial condensates of anepoxy-functional silane, from about 1 to about 90 weight percent, basedon the total weight of the composition, of a carboxylic acid functionalcompound selected from the group consisting of carboxylic acids,multifunctional carboxylic acids, anhydrides, and combinations thereof,from about 1 to 90 weight percent, based on the total solids of thecomposition, of a metal oxide composite colloid, and from about 1 to 75weight percent, based on the total solids of the composition, of adisilane.

The coating compositions of the present invention may further includefrom about 0.1 to about 50 weight percent, based on the total solids ofthe composition of a mixture of hydrolysis products and partialcondensates of one or more silane additives, from about 0.1 to 75 weightpercent, based on the total solids of the composition, of a colloidalsilica material, from about 0.1 to 75 weight percent, based on the totalsolids of the composition, of a tetrafunctional silane.

It is an object of the present invention to provide coating compositionsand methods of making and using said compositions having improvedstability, which form transparent coatings upon curing. It is a furtherobject of the present invention to provide stable coating compositions,which form transparent coatings upon curing and which also have improvedadhesion properties, improved resistance to crack formation, and amatched refractive index to that of the substrate.

Other objects, advantages and features of the present invention willbecome apparent upon reading the following detailed description inconjunction with the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description. The invention is capable of otherembodiments or of being practiced or carried out in various ways. Also,it is to be understood that the phraseology and terminology employedherein is for the purpose of description and should not be regarded aslimiting.

The present invention relates to coating compositions having improvedstability which, when applied to a variety of substrates and cured, formsubstantially transparent coatings which possess improved adhesion,improved resistance to crack formation and have a matched refractiveindex to that of the substrate.

For measuring the refractive indexes of the cured coating compositions,each composition was applied to a cleanly etched lead-silicate glassplaque by dip coating at 2 inches per minute and curing for a period of1 hour at 120° C. The refractive indexes were measured using a Bauschand Lomb Abbe-3L refractometer. Either diiodomethane or1-bromonaphthalene was used as the contact liquid. The standardprocedures for measurement and instrument maintenance contained in theoperator's manual for the Bausch and Lomb Abbe-3L refractometer wereused for data gathering and processing. For testing coated samples,coating compositions were applied to ADC lenses and cured at atemperature of from 95° C. to 120° C. for a period of 3 hours.Semi-quantitative assessments of the extent of cracking and adhesionwere made using the following tests.

For testing adhesion of the coated articles the procedures of ASTMD-3359, i.e. the tape test, were followed.

A typical test for cracking, and adhesion consists of immersion of thecoated article in boiling water or boiling tap water tint for a periodof time, e. g. 1 hour, followed by inspection for crack formation andtesting for adhesion. Specifically, lenses were tested in BPI Black Tint(Brain Power, Inc.) under boiling conditions. In this test a bottle ofBPI tint (approximately 100 grams) was diluted to about 900 grams withtap water and brought to a boil. The coated article was immersed in theboiling solution for a period of 30 minutes. The coated article wasremoved from the tint solution and inspected for cracking and tested foradhesion.

For measuring the control of tint absorption, a typical test consists ofexposing the coated article to the tint mixture above which is in eitherdeionized or tap water for a period of fifteen minutes at a temperaturein the range between 90° C. and 100° C. The light transmittance ismeasured, using a Gardner XL-835 Colorimeter, in 15 minute intervals.

For testing abrasion resistance of coated substrates, any of a number ofquantitative test methods may be employed, including the Taber Test(ASTM D-4060), the Tumble Test and Standard Method for the ModifiedBayer Test, which is described in The AR Council of America StandardTesting Procedures section 5.2.5 and is a variation of the test method,ASTM F735-81. In addition, there are a number of qualitative testmethods that may be used for measuring abrasion resistance, includingthe Steel Wool Test and the Eraser Test. In the Steel Wool Test and theEraser Test, coated substrate samples are scratched under reproducibleconditions (constant load, frequency, etc.). The scratched test samplesare then compared and rated against standard samples. Asemi-quantitative application of these test methods involves the use ofan instrument, such as a Spectrophotometer or a Colorimeter, formeasuring the scratches on the coated substrate as a haze gain.

The measured abrasion resistance of a cured coating on a substrate,whether measured by the Modified Bayer Test, Taber Test, Steel WoolTest, Eraser Test, Tumble Test, etc. is a function, in part, of the curetemperature and cure time. In general, higher temperatures and longercure times result in higher measured abrasion resistance. Normally, thecure temperature and cure time are selected for compatibility with thesubstrate; although, sometimes less than optimum cure temperatures andcure times are used due to process and/or equipment limitations. It willbe recognized by those skilled in the art that other variables, such ascoating thickness and the nature of the substrate, will also have aneffect on the measured abrasion resistance. In general, for each type ofsubstrate and for each coating composition there will be an optimumcoating thickness. The optimum cure temperature, cure time, coatingthickness, and the like, can be readily determined empirically by thoseskilled in the art.

In the test method employed to determine the abrasion resistance of thecoating compositions of the present invention, a commercially availablealundum (grain code 1524, 12 grit, alundum ZF) sold by Norton AdvancedCeramics of Canada Inc., 8001 Daly Street, Niagara Falls, Ontario, wasused as the abrasive material. In this test, 540 grams alundum wasloaded into a 9 5/16″×6¾″ cradle fitted with four lenses. Each set offour lenses, typically two poly(diethylene glycol-bis-allyl carbonate)lenses, herein referred to as ADC lenses, and two coated lenses, weresubjected to a 4 inch stroke (the direction of the stroke coincidingwith the 9 5/16″ length of the cradle) at an oscillation frequency of300 strokes per minute for a total of 4 minutes. The lens cradle wasrepositioned by turning 180 degrees after the initial 2 minutes ofoscillations. Repositioning of the cradle was used to reduce the impactof any inconsistencies in the oscillating mechanism. The ADC referencelenses used were Silor 70 mm piano FSV lenses, purchased through Essilorof America, Inc. of St. Petersburg, Fla. The above described procedureis slightly modified from that which is described by the AR Council ofAmerica by increasing the weight of the alundum to accommodate theincreased surface area of the larger cradle. The cradle described aboveholds 4 lenses. The haze generated on the lenses was then measured on aGardner XL-835 Colorimeter. The haze gain for each lens was determinedas the difference between the initial haze on the lenses and the hazeafter testing. The ratio of the haze gain on the ADC reference lenses tothe haze gain on the coated sample lenses was then reported as theresultant abrasion resistance of the coating material. A ratio ofgreater than 1 indicates a coating which provides greater abrasionresistance the uncoated ADC reference lenses. This ratio is commonlyreferred to as the Bayer ratio, number or value. Coatings with highabrasion resistance possess larger Bayer numbers than coatings withlower abrasion resistance.

It should be understood that: (a) the descriptions herein of coatingsystems which contain epoxy-functional silanes, tetrafunctional silanes,disilanes, silane additives which do not contain an epoxy-functionalgroup, and the carboxylic acid component, refer to the incipient silanesand carboxylic acid components from which the coating system is formed,(b) when the epoxy-functional silanes, tetrafunctional silanes,disilanes, and silane additives which do not contain an epoxy-functionalgroup, are combined with the aqueous-organic solvent mixture under theappropriate conditions, a hydrolysis reaction occurs resulting inpartially or fully hydrolyzed species, (c) the resultant fully orpartially hydrolyzed species can combine to form mixtures ofmultifunctional oligomeric siloxane species, (d) the oligomeric siloxanespecies may or may not contain pendant hydroxy and pendant alkoxymoieties and will be comprised of a silicon-oxygen matrix which containsboth silicon-oxygen siloxane linkages and silicon-oxygen carboxylic acidcomponent linkages, and (e) the resultant mixtures are dynamicoligomeric suspensions that undergo structural changes which aredependent upon a multitude of factors including; temperature, pH, watercontent, catalyst concentration, and the like.

The coating compositions of the present invention comprise anaqueous-organic solvent mixture containing from about 10 to about 90weight percent, based on the total solids of the composition, of amixture of hydrolysis products and partial condensates of anepoxy-functional silane, from about 1 to about 90 weight percent, basedon the total weight of the composition, of a carboxylic acid functionalcompound selected from the group consisting of carboxylic acids,multifunctional carboxylic acids, anhydrides, and combinations thereof,from about 1 to 90 weight percent, based on the total solids of thecomposition, of a metal oxide composite colloid, and from about 1 to 75weight percent, based on the total solids of the composition, of adisilane.

The amount of epoxy-functional silane, carboxylic acid component, metaloxide composite sol, and disilane employed can vary widely and willgenerally be dependent upon the properties desired in the coatingcomposition and the cured coating, as well as the end use of thesubstrate to which the coating composition is applied. Generally,however, desirable results can be obtained where the molar ratio of theepoxy-functional silane component to the disilane component, and thecolloidal metal oxide component are present in the coating compositionat a ratio of from about 0.05:1 to 2:1 and the molar ratio of thedisilane silane component to the metal oxide composite colloid presentin the coating composition is present in a range of from about 0.01:1 toabout 50:1.

While the presence of water in the aqueous-organic solvent mixture isnecessary to form hydrolysis products of the silane components of themixture, the actual amount of water can vary widely. However, asufficient amount of water must be present in the aqueous-organicsolvent mixture to provide a substantially homogeneous coating mixtureof hydrolysis products and partial condensates of the alkoxy functionalsilanes (i.e., the epoxy-functional silane and other silane additivecomponents) which, when applied and cured on an article, provides asubstantially transparent coating. Such coatings can be obtained byemploying a stoichiometric amount of water, e.g., as required for thehydrolysis of the sum of the hydrolyzable alkoxy groups on the alkoxysilane components in the coating mixture.

The abrasion resistance of the coated article is affected by theconcentration of water in the incipient coating mixture, as well as thepresence and concentration of a condensation catalyst. For example,coating mixtures which contain a low concentration of water (e.g. astoichiometric concentration of water) require a optional mineral acidhydrolysis co-catalyst to ensure the sufficient hydrolysis necessary forthe formation of a homogeneous coating mixture and a condensationcatalyst to obtain coating compositions which possess the desiredabrasion resistance properties after curing. It is preferred that theamount of water present in the aqueous-organic solvent mixture rangefrom about 1 to about 10 equivalents of water for each hydrolyzablealkoxy group. The effective amount of water and the effective amount andtype of catalyst can be determined empirically.

The solvent constituent of the aqueous-organic solvent mixture of thecoating compositions of the present invention can be any solvent orcombination of solvents which is compatible with the epoxy-functionalsilane, the carboxylic acid component, the colloidal metal oxidecomponent, the colloidal silica component, the disilane, and thetetrafunctional silane. For example, the solvent constituent of theaqueous-organic solvent mixture may be an alcohol, ether, a glycol orglycol ether, a ketone, an ester, a glycolether acetate and mixturesthereof. Alcohols which can be employed as the solvent constituent arerepresented by the formula ROH where R is an alkyl group containing from1 to about 10 carbon atoms. Examples of alcohols which can be employedas the solvent constituent of the aqueous-organic solvent mixtureemployed in the practice of the present invention are methanol, ethanol,propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiarybutanol, cyclohexanol, pentanol, octanol, decanol, and mixtures thereof.

Glycols, ethers, and glycol ethers which can be employed as the solventconstituent of the aqueous-organic solvent mixture are represented bythe formula R¹—(OR²)_(x)—OR¹ where x is 0, 1, 2, 3 or 4, R¹ is hydrogenor an alkyl group containing from 1 to about 10 carbon atoms and R² isan alkylene group containing from 1 to about 10 carbon atoms andcombinations thereof.

Examples of glycols, ethers and glycol ethers having the above-definedformula and which may be used as the solvent constituent of theaqueous-organic solvent mixture of the coating compositions of thepresent invention are di-n-butylether, ethylene glycol dimethyl ether,propylene glycol dimethyl ether, propylene glycol methyl ether,dipropylene glycol methyl ether, tripropylene glycol methyl ether,dipropylene glycol dimethyl ether, tripropylene glycol dimethyl ether,ethylene glycol butyl ether, diethylene glycol butyl ether, ethyleneglycol dibutyl ether, ethylene glycol methyl ether, diethylene glycolethyl ether, diethylene glycol dimethyl ether, ethylene glycol ethylether, ethylene glycol diethyl ether, ethylene glycol, diethyleneglycol, triethylene glycol, propylene glycol, dipropylene glycol,tripropylene glycol, butylene glycol, dibutylene glycol, tributyleneglycol and mixtures thereof. In addition to the above, cyclic etherssuch as tetrahydrofuran and dioxane are suitable ethers for theaqueous-organic solvent mixture.

Examples of ketones suitable as the organic solvent constituent of theaqueous-organic solvent mixture are acetone, diacetone alcohol, methylethyl ketone, cyclohexanone, methyl isobutyl ketone and combinationsthereof.

Examples of esters suitable for the aqueous-organic solvent mixture areethyl acetate, n-propyl acetate, n-butyl acetate and combinationsthereof.

Examples of glycolether acetates suitable as the organic solventconstitutent of the aqueous-organic solvent mixture are propylene glycolmethyl ether acetate, dipropylene glycol methyl ether acetate, ethyl3-ethoxypropionate, ethylene glycol ethyl ether acetate and combinationsthereof.

The epoxy-functional silane useful in the formulation of the coatingcompositions of the present invention can be any epoxy-functional silanecompatible with the carboxylic acid component, the metal oxide compositecolloid, and the disilane component of the coating composition whichprovides a coating composition that, upon curing, produces asubstantially transparent, abrasion resistant coating with a refractiveindex substantially corresponding to the refractive index of thesubstrate to which the coating composition is applied and which exhibitsimproved adhesion and improved resistance to crack formation. Generally,such epoxy-functional silanes are represented by the formula R³_(x)Si(OR⁴)_(4-x) where x is an integer of 1, 2 or 3, R³ is H, an alkylgroup, a functionalized alkyl group, an alkylene group, an aryl group,an alkyl ether, and combinations thereof containing from 1 to about 10carbon atoms and having at least 1 epoxy-functional group, and R⁴ is H,an alkyl group containing from 1 to about 5 carbon atoms, an acetylgroup, a —Si(OR⁵)_(3−y)R⁶ _(y) group where y is an integer of 0, 1, 2,or 3, and combinations thereof where R⁵ is H, an alkyl group containingfrom 1 to about 5 carbon atoms, an acetyl group, or another—Si(OR⁵)_(3-y)R⁶ _(y) group and combinations thereof, and R⁶ is H, analkyl group, a functionalized alkyl group, an alkylene group, an arylgroup, an alkyl ether, and combinations thereof containing from 1 toabout 10 carbon atoms which may also contain an epoxy-functional group.

Examples of such epoxy-functional silanes areglycidoxymethyltrimethoxysilane, 3-glycidoxypropyltrihydroxysilane,3-glycidoxypropyldimethylhydroxysilane,3-glycidoxypropyltrimeth-oxysilane, 3-glycidoxypropyltriethoxysilane,3-glycidoxypropyidimethoxymethylsilane,3-glycidoxypropyidimethylmethoxysilane,3-glycidoxypropyltributoxysilane,1,3-bis(glycidoxypropyl)tetramethyldisiloxane,1,3bis(glycidoxypropyl)tetramethoxydisiloxane,1,3-bis(glycidoxypropyl)-1,3dimethyl-1,3-dimethoxydisiloxane,2,3-epoxypropyltrimethoxysilane, 3,4-epoxybutyltrimethoxysilane,6,7-epoxyheptyltrimethoxysilane, 9,10-epoxydecyltrimethoxysilane,1,3-bis(2,3-epoxypropyl)tetramethoxydisiloxane,1,3-bis(6,7-epoxy-heptyl)tetramethoxydisiloxane,2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like.

The coating compositions of the present invention contain any carboxylicacid component compatible with the epoxy-functional silane, thecolloidal metal oxide component, the colloidal silica component, thetetrafunctional silane, and the disilane. The carboxylic acid componentis capable of interacting with the hydrolysis products and partialcondensates of the epoxy-functional silane and the tetrafunctionalsilane to provide a coating composition which, upon curing, produces asubstantially transparent, abrasion resistant coating having improvedadhesion, improved crack resistance and which possesses a refractiveindex substantially corresponding to the refractive index of thesubstrate to which it is applied.

Carboxylic acid component as used herein is understood to include mono-and multi-functional carboxylic acids as well as anhydrides, whichproduce mono- and multifunctional carboxylic acids. Examples ofcarboxylic acids, which can be in the coating compositions of thepresent invention, include acetic acid, acrylic acid, methacrylic acid,formic acid, propionic acid, butanoic acid, benzoic acid, malic acid,aconitic acid (cis, trans), itaconic acid, succinic acid, malonic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, cyclohexyl succinic acid, 1,3,5 benzene tricarboxylicacid, 1,2,4,5 benzene tetracarboxylic acid, 1,4-cyclohexanedicarboxylicacid, 1,3-cyclohexanedicarboxylic acid, 1,1-cyclohexanediacetic acid,1,3-cyclohexanediacetic acid, 1,3,5-cyclohexanetricarboxylic acid andunsaturated dibasic acids such as fumaric acid and maleic acid andcombinations thereof.

Examples of anhydrides which can be employed to produce the carboxylicacid component of the coating compositions of the present inventioninclude the anhydrides of the above mentioned carboxylic acids such asacetic anhydride, propionic anhydride, acrylic anhydride, methacrylicanhydride and the cyclic anhydrides of the above mentioned dibasic acidssuch as succinic anhydride, itaconic anhydride, glutaric anhydride,trimellitic anhydride, pyromellitic anhydride, phthalic anhydride andmaleic anhydride and combinations thereof.

Optionally, in addition to the carboxylic acid component of the coatingcomposition, a mineral acid such as, for example, hydrochloric acid ornitric acid, can be used as a co-hydrolysis catalyst for the hydrolysisof the silane compounds described herein.

The disilane components useful in the coating compositions of thepresent invention can be any disilane which is compatible with thecarboxylic acid component, the metal oxide composite colloid, and theepoxy functional silane component of the coating composition and whichprovides a coating composition which, upon curing, produces asubstantially transparent, abrasion resistant coating having arefractive index substantially corresponding to the refractive index ofthe substrate to which the coating composition is applied and whichexhibits improved adhesion and improved resistance to crack formation.

Generally, such disilanes are represented by the formula (R⁷O)_(x)R⁸_(3-x)Si—R⁹ _(y)—SiR¹⁰ _(3-x)(OR¹¹)_(x); where x is 0, 1, 2 or 3 eitherH or an alkyl group containing from about 1 to 10 carbon atoms, afunctionalized alkyl group, an alkylene group, an aryl group, analkylpolyether group and combinations thereof; R⁷ and R¹¹ are either H,an alkyl group containing from about 1 to 10 carbon atoms, an acetylgroup, and combinations thereof. If y is 1 then R⁹ can be an alkylenegroup containing from about 1 to 12 carbon atoms, an alkylenepolyethercontaining from about 1 to 12 carbon atoms, an aryl group, an alkylenesubstituted aryl group, an alkylene group which may contain one or moreolefins, or an oxygen or sulfur atom. If x=0 then R⁸ and R¹⁰ is achlorine or bromine atom. If y=0 then there is a direct silicon-siliconbond.

Examples of disilanes satisfying the above defined formula include;bis(triethoxysilyl)ethane, bis(triethoxysilyl)methane,bis(trichlorosilyl)methane, bis(triethoxysilyl)ethylene, 1,3bistriethoxysilylethane, hexaethoxydisiloxane, hexaethoxydisilane.

The metal oxide colloidal component of the present invention may consistof a single component metal oxide colloid or a complex composite metaloxide colloid consisting of more than one metal oxide component. Therefractive index of the colloidal metal oxide component should besufficiently higher than the coating mixture so the addition ofeffective amounts of the colloidal metal oxide component can yield adesirable refractive index for the entire coating composition. Thecolloidal metal oxide component may contain any combination of titania,zirconia, tin oxide, antimony oxide, iron oxide, lead oxide, and/orbismuth oxide for purposes of increasing the refractive index. Thecolloidal metal oxide component may also contain alumina and/or silica.

In general, it is preferred that the colloidal metal oxide componentused in the present invention consist of a composite mixture of two ormore metal oxide components listed above where at least one of the metaloxide components present in the composite mixture is neither alumina norsilica. Examples of commercially available metal oxide colloidalmaterials and composite metal oxide component materials are theSuncolloid series AMT-130S, HIS-33M, HIT-30M, and HIT-32M from NissanChemical Industries LTD., Optolake 1130F-2(A-8), 2130F-2(A-8), OptolakeARC-7, and Queen Titanic-11-1 from Catalyst and Chemical Industries LTD.

Proper selection of the amounts and type of the colloidal metal oxidecomponent, the epoxy-functional silane, the carboxylic acid component,the colloidal silica component, the tetrafunctional silane component,the disilane component, and if desired, the optional silane componentand condensation catalyst will yield a cured coating material with arefractive index in the range from 1.4 to greater than 1.7.

The coating compositions of the present invention are also stable withrespect to aging, both in terms of performance and solution stability.The aging of the coating composition is characterized by a gradualincrease in viscosity, which eventually renders the coating compositionsunusable due to processing constraints. The coating compositions of thepresent invention, when stored at temperatures of 5° C. or lower haveusable shelf lives of 3–4 months. During this period, the abrasionresistance of the cured coatings does not significantly decrease withtime. The abrasion resistant coating compositions which provideindex-matching properties described in the present invention areachieved through the unique combination of an epoxy-functional silane, acarboxylic acid component, a composite metal oxide colloid, a colloidalsilica component, and a tetrafunctional silane. The coating compositionsmay optionally include other materials which may: (a) enhance thestability of the coating compositions; (b) increase the abrasionresistance of cured coatings produced by the coating compositions; (c)improve processing of the coating compositions; and (d) provide otherdesirable properties to the coating composition and the cured product ofthe coating compositions.

The present invention may include a colloidal silica component, whichcan be either an aqueous or non-aqueous based material. The colloidalsilica component may exist in the coating composition from about 0.1 to75 weight percent, based on the total solids of the composition. Thecolloidal silica is an aqueous or non-aqueous solvent dispersion ofparticulate silica and the various products differ principally byparticle size, silica concentration, pH, presence of stabilizing ions,solvent makeup, and the like. Colloidal silica is commercially availableunder a number of different tradename designations, including Nalcoag®(Nalco Chemical Co., Naperville, Ill.); Nyacol® (Nyacol Products, Inc.,Ashland, Mass.); Snowtex® (Nissan Chemical Industries, LTD., Tokyo,Japan); Ludox® (DuPont Company, Wilmington, Del.); and Highlink OG®(Hoechst Celanese, Charlotte, N.C.). It should be noted thatsubstantially different product properties can be obtained through theselection of different colloidal silicas.

Colloids which possess acidic pH values and very slightly basic pHvalues with low levels of sodium are preferred. These colloidal silicamaterials provide an increase in the abrasion resistance and provide aresistance to crack formation, which can result from exposure of thecured coatings to boiling tap water tint baths, vide supra. Examples ofpreferred colloidal silica materials are Nalco® 1042 and Nalco® 1040 andthe like. Basic colloidal silica materials which possess higher pHvalues and/or a higher concentration of sodium ions result in curedcoating compositions which possess abrasion resistance which is lowerthan that which results from the use of the preferred colloidal silicamaterials and are not preferred. An example of a material, which is notpreferred, is Nalco® 1115 and the like.

Tetrafunctional silanes may also be useful in the formulation of thecoating compositions of the present invention and may exist from about0.1 to about 75 weight percent based on the total solids of thecomposition. The tetrafunctional silanes are represented by the formulaSi(OR⁷)₄ where R⁷ is H, an alkyl group containing from 1 to about 5carbon atoms and ethers thereof, an (OR⁷) carboxylate, a —Si(OR⁸)₃ groupwhere R⁸ is a H, an alkyl group containing from 1 to about 5 carbonatoms and ethers thereof, an (OR⁷) carboxylate, or another —Si(OR⁸)₃group and combinations thereof.

Examples of tetrafunctional silanes represented by the formula Si(OR⁷)₄are tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropylorthosilicate, tetraisopropyl orthosilicate, tetrabutyl ortho-silicate,tetraisobutyl orthosilicate, tetrakis(methoxyethoxy) silane,tetrakis(methoxypropoxy)silane, tetrakis(ethoxyethoxy) silane,tetrakis(methoxyethoxyethoxy)silane, trimethoxyethoxysilane,dimethoxydiethoxysilane, triethoxymethoxysilane, poly(dimethoxysiloxane), poly(diethoxysiloxane),poly(dimethoxy-diethoxysiloxane), tetrakis(trimethoxysiloxy)silane,tetrakis-(triethoxysiloxy)silane, and the like. In addition to the R⁷and R⁸ substituants described above for the tetrafunctional silane, R⁷and R⁸ taken with oxygen (OR⁷) and (OR⁸) can be carboxylate groups.Examples of tetrafunctional silanes with carboxylate functionalities aresilicon tetracetate, silicon tetrapropionate and silicon tetrabutyrate.

The coating compositions of the present invention may further includefrom about 0.1 to about 50 weight percent, based on the weight of totalsolids of the coating compositions, of a mixture of hydrolysis productsand partial condensates of one or more silane additives (i.e,trifunctional silanes, difunctional silanes, monofunctional silanes, andmixtures thereof). The selection of the silane additives incorporatedinto the coating compositions of the present invention will depend uponthe particular properties to be enhanced or imparted to either thecoating composition or the cured coating composition. The silaneadditives can be represented by the formula R⁹ _(x)Si(OR¹⁰)_(4-x) wherex is a 1, 2 or 3; R⁹ is H, or an alkyl group containing from 1 to about10 carbon atoms, a functionalized alkyl group, an alkylene group, anaryl group an alkyl ether group and combinations thereof; R¹⁰ is H, analkyl group containing from 1 to about 10 carbon atoms, an acetyl group,a —Si(OR¹⁰)₃ group and combinations thereof.

Examples of silane additives represented by the above-defined formulaare methyltrimethoxysilane, ethyltrimethoxysilane,propyltrimethoxysilane, butyltrimethoxysilane,isobutyltrimethoxy-silane, hexyltrimethoxysilane, octyltrimethoxysilane,decyltrimethoxysilane, cyclohexyltrimethoxysilane,cyclohexylmethyltrimethoxysilane, 3methacryloxypropyltrimethoxysilane,vinyltrimethoxysilane, allyltrimethoxysilane, dimethyldimethoxysilane,2-(3cyclohexenyl)ethyltrimethoxysilane, 3-cyanopropyltrimethoxysilane,3-chloropropyltrimethoxysilane, 2-chloroethyltrimethoxysilane,phenethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane,3-aminopropyltrimethoxysilane, phenyltrimethoxysilane,3-isocyanopropyltrimethoxysilane, N-(2-aminoethyl )-3-aminopropyltrimethoxysilane,4-(2-aminoethylaminomethyl)phenethyltrimethoxysiane,chloromethyltriethoxysilane, 2-chloroethyltriethoxysilane,3-chloropropyltriethoxysilane, phenyltriethoxysilane,ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane,isobutyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane,decyltriethoxysilane, cyclohexyltriethoxysilane,cyclohexylmethyltriethoxysilane, 3-methacryloxypropyltriethoxysilane,vinyltriethoxysilane, allyltriethoxysilane,[2(3-cyclohexenyl)ethyltriethoxysilane, 3-cyanopropyltriethoxy-silane,3-methacrylamidopropyltriethoxysilane, 3-methoxypropyltrimethoxysilane,3-ethoxypropyltrimethoxysilane, 3-propoxypropyl-trimethoxysilane,3-methoxyethyltrimethoxysilane, 3-ethoxyethyltrimethoxysilane,3-propoxyethyltrimethoxysilane,2-[methoxy(polyethyleneoxy)propyl]heptamethyltrisiloxane,[methoxy(polyethyleneoxy)propyl]trimethoxysilane,[methoxy(polyethyleneoxy)ethyl]-trimethoxysilane,[methoxy(polyethyleneoxy)propyl]triethoxysilane,[methoxy(poly-ethyleneoxy)ethyl]triethoxysilane, and the like.

Although a condensation catalyst is not an essential ingredient of thecoating compositions of the present invention, the addition of acondensation catalyst can affect abrasion resistance and otherproperties of the coating including stability, tinting capacity,porosity, cosmetics, caustic resistance, water resistance and the like.When employing a condensation catalyst, the amount of catalyst used canvary widely, but will generally be present in an amount from about 0.05to about 20 weight percent, based on the total solids of thecomposition.

Examples of catalysts which can be incorporated into the coatingcompositions of the present invention are (i) metal acetylacetonates,(ii) diamides, (iii) imidazoles, (iv) amines and ammonium salts, (v)organic sulfonic acids and their amine salts, (vi) alkali metal salts ofcarboxylic acids, (vii) alkali metal hydroxides, (viii) fluoride salts,and (ix) organostannanes. Thus, examples of such catalysts include forgroup (i) such compounds as aluminum, zinc, iron and cobaltacetylacetonates; group (ii) dicyandiamide; for group (iii) suchcompounds as 2-methylimidazole, 2-ethyl-4-methylimidazole and1-cyanoethyl-2-propylimidazole; for group (iv), such compounds asbenzyldimethylamine, and 1,2-diaminocyclohexane; for group (v), suchcompounds as trifluoromethanesulfonic acid; for group (vi), suchcompounds as sodium acetate, for group (vii), such compounds as sodiumhydroxide, and potassium hydroxide, for group (viii), tetra n-butylammonium fluoride, and for group (ix), dibutyltin dilaurate, and thelike.

An effective amount of a leveling or flow control agent can beincorporated into the composition to more evenly spread or level thecomposition on the surface of the substrate and to provide substantiallyuniform contact with the substrate. The amount of the leveling or flowcontrol agent can vary widely, but generally is an amount sufficient toprovide the coating composition with from about 10 to about 50,000 ppmof the leveling or flow control agent. Any conventional, commerciallyavailable leveling or flow control agent which is compatible with thecoating composition and the substrate and which is capable of levelingthe coating composition on a substrate and which enhances wettingbetween the coating composition and the substrate can be employed. Theuse of leveling and flow control agents is well known in the art and hasbeen described in the “Handbook of Coating Additives” (ed. Leonard J.Calbo, pub. Marcel Dekker), pg 119–145.

Examples of such leveling or flow control agents which can beincorporated into the coating compositions of the present inventioninclude organic polyethers such as TRITON X-100, X-405, N-57 from Rohmand Haas, silicones such as Paint Additive 3, Paint Additive 29, PaintAdditive 57 from Dow Corning, SILWET L-77, and SILWET L-7600 from OSiSpecialties, and fluorosurfactants such as FLUORAD FC-171, FLUORADFC-430 and FLUORAD FC-431 from 3M Corporation.

In addition, other additives can be added to the coating compositions ofthe present invention in order to enhance the usefulness of the coatingcompositions or the coatings produced by curing the. coatingcompositions. For example, ultraviolet absorbers, antioxidants, and thelike can be incorporated into the coating compositions of the presentinvention, if desired.

The coating compositions of the present invention can be prepared by avariety of processes to provide stable coating compositions, which, uponcuring, produce substantially transparent abrasion resistant coatingshaving improved abrasion resistance, resistance to crack formation, anda matched refractive index.

The preferred method for preparing the coating compositions of thepresent invention consists of the initial hydrolysis of theepoxy-functional silane by addition of the silane to a mixture ofdeionized water, the acid component, and the solvent constituent. Aftersufficient time for the hydrolysis, the disilane is added and theresultant mixture is allowed to stir for a sufficient period of time forhydrolysis. When desired, a condensation catalyst and/or a surfactantfor leveling and flow improvement may be added to the final coatingcomposition.

The coating compositions of the present invention can be applied tosolid substrates by conventional methods, such as flow coating, spraycoating, curtain coating, dip coating, spin coating, roll coating, etc.to form a continuous surface film. Any substrate compatible with thecompositions can be coated with the compositions, such as plasticmaterials, wood, paper, metal, printed surfaces, leather, glass,ceramics, glass ceramics, mineral based materials and textiles. Thecompositions are especially useful as coatings for synthetic organicpolymeric substrates in sheet or film form, such as acrylic polymers,poly(ethyleneterephthalate), polycarbonates, polyamides, polyimides,copolymers of acrylonitrile-styrene, styrene-acrylonitrile-butadienecopolymers, polyvinyl chloride, butyrates, polyethylene and the like.Transparent polymeric materials coated with these compositions areuseful as flat or curved enclosures, such as windows, liquid crystaldisplay screens, skylights and windshields, especially fortransportation equipment. Plastic lenses, such as acrylic orpolycarbonate ophthalmic lenses, can also be coated with thecompositions of the invention.

By choice of proper formulation, application conditions and pretreatment(including the use of primers) of the substrate, the coatingcompositions of the present invention can be adhered to substantiallyall solid surfaces. Abrasion resistant coatings having improved adhesionand resistance to cracking can be obtained from coating compositions ofthe present invention by heat curing at temperatures in the range offrom about 50° C. to about 200° C. for a period of from about 5 minutesto about 18 hours. The coating thickness can be varied by means of theparticular application technique, but coatings having a thickness offrom about 0.5 to about 20 microns, and more desirably from about 1 toabout 10 microns, are generally utilized.

In order to further illustrate the present invention, the followingexamples are given. However, it is to be understood that the examplesare for illustrative purposes only and are not to be construed aslimiting the scope of the subject invention.ed.

EXAMPLES

Procedure

Etched poly(diethylene glycol-bis-allyl carbonate) lenses and plaques(referred to as ADC lenses or ADC plaques) were use for coating andtesting. The ADC lenses and plaques were etched by contact with a 10%potassium hydroxide solution containing propylene glycol methyl etherand water for a period of about 10 minutes. The lenses and/or plaqueswere coated by dip coating using a specified withdrawal rate in units ofinches per minute (ipm). The lenses and/or plaques were cured at atemperature of 110° C. for 3 hours. The lenses and/or plaques weresubjected to the afore-mentioned test procedures to determine adhesion,resistance to cracking and abrasion resistance. The 1.7 R_(I) glassplaques were cleaned by etching in 20 percent KOH followed by rinsingwith D.I. water. The coating was applied to the 1,7 R_(I) plaques bydipping at 2 ipm followed by curing for 1 hour at 110° C. The R_(I) wasmeasured according to the procedure described vide supra.

Example 1

55.5 grams of GPTMS were added dropwise to a stirring solution of 94.1grams of deionized water, 94.1 grams of propylene glycol methyl ether(PMOH), and 8.7 grams of acetic acid (AcOH). After stirring for a periodof 4 hours 55.5 grams of Bis(triethoxysilyl)ethane (BSE) were addeddropwise and resulting mixture was stirred overnight. 92.0 grams ofOptolake2130f-2(A-8), a colloidal metal oxide, were added dropwise tothe above mixture while stirring. The resulting mixture was stirred for4 hours to yield a coating composition.

Example 1A

1.6 grams of a solution of FC-430 (3M), 10 weight percent in PMOH, wereadded to 190 grams of the coating composition, as described inexample 1. The coating composition was left to stir for an additional 20minutes after the addition of the FC-430 to insure mixing. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.2microns, a refractive index of about 1.59, and a Bayer number of 6.6.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 15 minutes yielded a coated article with 89 percent L.T.

Example 1B

1.9 grams of dicyandiamide (DCDA) were added to 188.1 grams of thecoating composition, described in example 1 above, followed by dilutionwith 6.8 grams of a 50 weight percent mixture of PMOH in deionizedwater. The mixture was left to stir overnight followed by addition of a1.5 gram solution of FC-430 (3M) 10 weight percent in PMOH. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.3microns, a refractive index of about 1.58, and a Bayer number of 9.3.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 15 minutes yielded a coated article with 84 percent L.T.

Example 2

50.1 grams of GPTMS were added dropwise to a stirring solution of 104.1grams of deionized water, 104.1 grams of PMOH, and 8.5 grams of itaconicacid (ITA). After stirring for a period of 4 hours 50.1 grams of BSEwere added dropwise and resulting mixture was stirred overnight. 83.1grams of Optolake2130f-2(A-8), a colloidal metal oxide, were addeddropwise to the above mixture while stirring. The resulting mixture wasstirred for 4 hours to yield a coating composition.

Example 2A

1.6 grams of a solution of FC-430 (3M), 10 weight percent in PMOH, wereadded to 190 grams of the coating composition, as described in example2. The coating composition was left to stir for an additional 20 minutesafter the addition of the FC-430 to insure mixing. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.3microns, a refractive index of about 1.58, and a Bayer number of 5.1.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 15 minutes yielded a coated article with 78 percent L.T.

Example 2B

1.7 grams of dicyandiamide (DCDA) were added to 188.3 grams of thecoating composition, described in example 2 above, followed by dilutionwith 6.0 grams of a 50 weight percent mixture of PMOH in deionizedwater. The mixture was left to stir overnight followed by addition of a1.5 gram solution of FC-430 (3M) 10 weight percent in PMOH. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.1microns, a refractive index of about 1.60, and a Bayer number of 10.1.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 15 minutes yielded a coated article with 87 percent L.T.

Example 3A

74.5 grams of GPTMS were added dropwise to a stirring solution of 158.5grams of deionized water, 158.5 grams of PMOH, and 12.8 grams of ITA.After stirring for a period of 1 hour, a stirred mixture of 47.8 gramsof BSE and 18.8 grams of TEOS were added dropwise and resulting mixturewas stirred overnight. The resulting mixture was split into 3, 117 gramportions. To one portion, 41.3 grams of Optolake2130f-2(A-8), acolloidal metal oxide, were added dropwise, and the resulting mixturewas stirred overnight to produce a coating composition. 39.8 grams of a4.5 weight percent solution of DCDA in PMOH were added to the coatingcomposition and the resulting mixture was stirred overnight followed byaddition of 0.15 grams of a 10 weight percent solution of PA-57 in PMOHand further stirring for 20 minutes. This coating composition wasapplied to etched ADC lenses, ADC plaques, and 1.7 R_(I) glass plaques,according to the procedure above, at a withdrawal rate of 2 ipm toprovide a cured coating having a thickness of about 2.1 microns, arefractive index of about 1.60, and a Bayer number of 6.0. Exposure of acoated ADC plaque to boiling tap water tint for a period of 30 minutesyielded a coated article with 42 percent L.T.

Example 3B

73.3 grams of GPTMS were added dropwise to a stirring solution of 158.3grams of deionized water, 158.3 grams of PMOH, and 12.6 grams of ITA.After stirring for a period of 1 hour, a stirred mixture of 58.9 gramsof BSE and 11.5 grams of TEOS were added dropwise and resulting mixturewas stirred overnight. The resulting mixture was split into 3, 119 gramportions. To one portion, 40.6 grams of Optolake2130f-2(A-8), acolloidal metal oxide, were added dropwise, and the resulting mixturewas stirred overnight to produce a coating composition. 37.8 grams of a4.5 weight percent solution of DCDA in PMOH were added to the coatingcomposition and the resulting mixture was stirred overnight followed byaddition of 0.15 grams of a 10 weight percent solution of PA-57 in PMOHand further stirring for 20 minutes. This coating composition wasapplied to etched ADC lenses, ADC plaques, and 1.7 R_(I) glass plaques,according to the procedure above, at a withdrawal rate of 2 ipm toprovide a cured coating having a thickness of about 1.9 microns, arefractive index of about 1.60, and a Bayer number of 5.8. Exposure of acoated ADC plaque to boiling tap water tint for a period of 30 minutesyielded a coated article with 85 percent L.T.

Example 4

48.3 grams of GPTMS were added dropwise to a stirring solution of 109.0grams of deionized water, 109.0 grams of IPA, and 8.3 grams of ITA.After stirring for a period of 2 hours, a stirred mixture of 31.0 gramsof BSE and 2.4 grams of TEOS were added dropwise and resulting mixturewas stirred overnight.

Example 4A

To 154 grams of the mixture in example 4 were added 4.1 grams of Nalco1042 colloidal silica, followed by stirring for 4 hours. To this mixture40.2 grams of Optolake2130f-2(A-8), a colloidal metal oxide, were addeddropwise, and the resulting mixture was stirred overnight to produce acoating composition. 0.15 grams of a 10 weight percent solution of PA-57in PMOH were added to the above mixture, followed by further stirringfor 20 minutes. This coating composition was applied to etched ADClenses, ADC plaques, and 1.7 R_(I) glass plaques, according to theprocedure above, at a withdrawal rate of 2 ipm to provide a curedcoating having a thickness of about 2.0 microns, a refractive index ofabout 1.60, and a Bayer number of 4.2. Exposure of a coated ADC plaqueto boiling tap water tint for a period of 30 minutes yielded a coatedarticle with 81 percent L.T.

Example 4B

To example 4A above were added 3.4 grams of solid DCDA and the mixturewas stirred overnight to produce a coating composition. 0.15 grams of a10 weight percent solution of PA-57 in PMOH were added to the abovecomposition, followed by further stirring for 20 minutes. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.1microns, a refractive index of about 1.60, and a Bayer number of 5.3.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 30 minutes yielded a coated article with 68 percent L.T.

Example 5

48.5 grams of GPTMS were added dropwise to a stirring solution of 109.3grams of deionized water, 109.3 grams of IPA, and 8.3 grams of ITA.After stirring for a period of 2 hours, a stirred mixture of 31.1 gramsof BSE and 2.4 grams of TEOS were added dropwise and resulting mixturewas stirred overnight.

Example 5A

To 154 grams of the mixture in example 10 were added 3.5 grams of Nalco1040 colloidal silica, followed by stirring for 4 hours. To this mixture40.2 grams of Optolake2130f-2(A-8), a colloidal metal oxide, were addeddropwise, and the resulting mixture was stirred overnight to produce acoating composition. 0.15 grams of a 10 weight percent solution of PA-57in PMOH were added to the above mixture, followed by further stirringfor 20 minutes. This coating composition was applied to etched ADClenses, ADC plaques, and 1.7 R_(I) glass plaques, according to theprocedure above, at a withdrawal rate of 2 ipm to provide a curedcoating having a thickness of about 1.9 microns, a refractive index ofabout 1.60, and a Bayer number of 4.3. Exposure of a coated ADC plaqueto boiling tap water tint for a period of 30 minutes yielded a coatedarticle with 63 percent L.T.

Example 5B

To example 11A above were added 3.5 grams of solid DCDA and the mixturewas stirred overnight to produce a coating composition. 0.15 grams of a10 weight percent solution of PA-57 in PMOH were added to the abovecomposition, followed by further stirring for 20 minutes. This coatingcomposition was applied to etched ADC lenses, ADC plaques, and 1.7 R_(I)glass plaques, according to the procedure above, at a withdrawal rate of2 ipm to provide a cured coating having a thickness of about 2.0microns, a refractive index of about 1.60, and a Bayer number of 5.9.Exposure of a coated ADC plaque to boiling tap water tint for a periodof 30 minutes yielded a coated. article with 76 percent L.T.

Thus, it should be apparent that there has been provided in accordancewith the present invention a coating composition and a method for makingand using same that fully satisfy the objectives and advantages setforth above. Although the invention has been described in conjunctionwith specific embodiments thereof, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims. Changes may be made in the construction and theoperation of the various components, elements and assemblies describedherein and changes may be made in the steps or the sequence of steps ofthe methods described herein without departing from the spirit and scopeof the invention as defined in the following claims.

1. An article comprising: a substrate; and a substantially transparentabrasion-resistant coating formed on at least one surface of thesubstrate, the coating having a refractive index substantiallycorresponding to a refractive index of the substrate and being formed bycuring a coating composition, the coating composition comprising anaqueous-organic solvent mixture containing hydrolysis products andpartial condensates of an epoxy functional silane, a metal oxidecomposite colloid, a disilane and a carboxylic acid functional compoundwherein the dlsilane is represented by the formula (R¹⁰O)_(x)R¹¹_(3-x)Si—R¹² _(y)—SiR¹³ _(3-x)(OR¹⁴)_(x), where x is 0, 1, 2 or 3 and yis 0 or 1, R¹⁰ and R¹³ are H or an alkyl group containing from about 1to 10 carbon atoms, a functionalized alkyl group, an alkylene group, anaryl group, an alkylpolyether group and combinations thereof, R¹⁰ andR¹² are H, an alkyl group containing from about 1 to 10 carbon atoms, anacetyl group, and combinations thereof, wherein if y is 1 then R¹² canbe an alkylene group containing from about 1 to 12 carbon atoms, analkylenepolyether containing from about 1 to 12 carbon atoms, an arylgroup, an alkylene substituted aryl group, an alkylene group which maycontain one or more olefins, or an oxygen or sulfur atom, and furtherwherein if x=0 then R¹¹ and R¹³ is a chlorine or bromine atom, andwherein the carboxylic acid functional compound is selected from thegroup consisting of monofunctional carboxylic acids, multifunctionalcarboxylic acids, anhydrides, and combinations thereof, and furtherwherein the epoxy functional sliane is present in a molar ratio to thedisilane component and the metal oxide composite colloid component offrom about 0.1:1 to 4:1.
 2. The article of claim 1 wherein thehydrolysis products and partial condensates of the epoxy functionalsilane are present in the aqueous-organic solvent mixture In an amountfrom about 10 to about 90 weight percent, based on the total solids ofthe composition.
 3. The article of claim 1 wherein the carboxylic acidfunctional compound is present in the aqueous-organic solvent mixture inan amount of from about 0.01 to 90 weight percent, based on the totalweight of the composition.
 4. The article of claim 1 wherein thedisilane component Is present in the aqueous-organic solvent mixture inan amount of from about 0.01 to 85 weight percent, based on the totalsolids of the composition.
 5. The article of claim 1 wherein the metaloxide composite colloid component is present in the aqueous-organicsolvent mixture in an amount of from about 0.01 to 80 weight percent,based on the total solids of the composition.
 6. The article of claim 1wherein the solvent constituent of the aqueous-organic solvent mixtureis selected from the group consisting of an alcohol, an ether, a glycolether, an ester, a ketone, a glycolether acetate and combinationsthereof.
 7. The article of claim 1 wherein the solvent constituent ofthe aqueous-organic solvent mixture is an alcohol having the generalformula ROH where R is an alkyl group containing from about 1 to about10 carbon atoms.
 8. The article of claim 1 wherein the solventconstituent of the aqueous-organic solvent mixture is selected from thegroup consisting of a glycol, an ether, a glycol ether and mixturesthereof having the formula R¹—(OR²)_(x)—OR¹ where x is an integer of 0,1, 2, 3, or 4, R¹ is H or an alkyl group containing from about 1 toabout 10 carbon atoms and R² is an alkylene group containing from about1 to about 10 carbons atoms and combinations thereof.
 9. The article ofclaim 1 wherein the epoxy functional sliane present in theaqueous-organic solvent mixture is represented by the formula R⁴_(x)Si(OR⁵)_(4-x) where x is an integer of 1, 2 or 3, R⁴ is H, an alkylgroup, a functionalized alkyl group, an alkylene group, an aryl group,an alkyl ether, and combinations thereof containing from 1 to about 10carbon atoms and having at least 1 epoxy functional group, and R⁵ is H,an alkyl group containing from 1 to about 5 carbon atoms, an acetylgroup, a —Si(OR⁶)_(3-x)R⁷ _(y) group where y is an integer of 0, 1, 2,or 3, where R⁶ is H, an alkyl group containing from 1 to about 5 carbonatoms an acetyl group, another —Si(OR⁶)_(3-y)R⁷ _(y) group andcombinations thereof, and R⁶ is H, an alkyl group, a functionalizedalkyl group, an alkylene group, an aryl group, an alkyl ether andcombinations thereof containing from 1 to about 10 carbon atoms.
 10. Thearticle of claim 1 wherein the carboxylic acid functional compoundpresent in the aqueous-organic solvent mixture is represented by theformula R⁸(COOR⁹)_(x) where x is an integer of 1, 2, 3, or 4, and whereR⁸ is H, an alkyl group, a functionalized alkyl group, an alkylenegroup, an aryl group, a functionalized aryl group, an alkyl ether, andcombinations thereof containing from 1 to about 10 carbon atoms, andwhere R⁹ is H, a formyl group, a carbonyl group, or an acyl group, wherethe acyl group can be functionalized with an alkyl group, afunctionalized alkyl group, an alkylene group, an aryl group, afunctionalized aryl group, an alkyl ether, and combinations thereofcontaining from 1 to about 10 carbon atoms, and where R⁸ and R⁹ may ormay not be joined by a chemical bond.
 11. The article of claim 1 whereinthe aqueous-organic solvent mixture further contains alumina, silica,titania, zirconia, tin oxide, antimony oxide, iron oxide, lead oxide,bismuth oxide, and combinations thereof and wherein at least one of themetal oxide components present in the composite mixture is neitheralumina nor silica.
 12. The article of claim 1 wherein the amount ofwater present in the aqueous-organic solvent mixture is an amountsufficient to provide a substantially homogeneous mixture of hydrolysisproducts and partial condensates of all reactive components.
 13. Thearticle of claim 12 wherein the aqueous-organic solvent mixture furthercontains an effective amount of co-hydrolysis catalyst thereby enhancingthe hydrolysis rates of the hydrolyzable components.
 14. The article ofclaim 1 wherein the aqueous-organic mixture further contains aneffective amount of a catalyst thereby providing enhanced abrasionresistance to a coating produced by curing the composition.
 15. Thearticle of claim 14 wherein the effective amount of the catalyst presentin aqueous-organic solvent mixture is from about 0.01 to about 2 weightpercent, based on the total solids of the composition.
 16. The articleof claim 1 wherein the aqueous-organic solvent mixture further comprisesan effective amount of a leveling agent thereby allowing theaqueous-organic solvent mixture to be spread on the substrate therebyproviding substantially uniform contact of the aqueous-organic solventmixture with the substrate.
 17. The article of claim 1 wherein theaqueous-organic solvent mixture further comprises from about 0.1 toabout 70 weight percent, based on the total solids of the composition,of a mixture of hydrolysis products and partial condensates of a silaneadditive represented by the formula R¹⁵ _(x)Si(OR¹⁶)_(4-x) where x is aninteger of 0, 1, 2 or 3, R¹⁵ is H, an alkyl group containing from 1 toabout 10 carbon atoms, a functionalized alkyl group, an alkylene group,an aryl group an alkyl ether group and combinations thereof, R¹⁶ is H,an alkyl group containing from 1 to about 10 carbon atoms, an acetylgroup and combinations thereof.
 18. The article of claim 17 wherein theamount of water present in the aqueous-organic solvent mixture is anamount sufficient to provide a substantially homogeneous mixture ofhydrolysis products and partial condensates of all reactive components.19. The article of claim 18 wherein the aqueous-organic solvent mixturefurther comprises an effective amount of co-hydrolysis catalyst therebyenhancing the hydrolysis rates of the hydrolyzable components.
 20. Thearticle of claim 19 wherein the aqueous-organic solvent mixture furthercomprises an effective amount of a catalyst thereby providing enhancedabrasion resistance to a cured coating.
 21. The article of claim 20wherein the effective amount of the catalyst is from about 0.01 to about2 weight percent, based on the total solids of the composition.
 22. Thearticle of claim 19 wherein the aqueous-organic solvent mixture furthercomprises an effective amount of a leveling agent thereby allowing theaqueous-organic solvent mixture to be spread on the substrate therebyproviding substantially uniform contact of the aqueous-organic solventmixture with the substrate.
 23. An article having an abrasion resistantcoating found on at least one surface thereof, the abrasion resistantcoating further having a refractive index, the abrasion resistantcoating formed by applying an aqueous-organic solvent mixture to atleast one surface of the article and thereafter curing theaqueous-organic solvent mixture to provide the abrasion resistantcoating, the aqueous-organic solvent mixture comprising: hydrolysisproducts and partial condensates of an epoxy functional silane, a metaloxide composite colloid, a disilane, a carboxylic acid functionalcompound is selected from the group consisting of monofunctionalcarboxylic acids, multifunctional carboxylic acids, anhydrides andcombinations thereof, and from about 0.1 to about 70 weight percent,based on the total solids of the aqueous-organic solvent mixture, of amixture of hydrolysis products and partial condensates of a silaneadditive represented by the formula R¹⁵ _(x)Si(OR¹⁶)_(4-x) where x is aninteger of 0, 1, 2 or 3, R¹⁵ is H, an alkyl group containing from 1 toabout 10 carbon atoms, a functionalized alkyl group, an alkylene group,an aryl group, an alkyl ether group and combinations thereof, R¹⁶ is H,an alkyl group containing from 1 to about 10 carbon atoms, an acetylgroup and combinations thereof wherein the disilane is represented bythe formula (R¹⁰)_(x) R¹¹ _(3-x)Si—R¹² _(y—SiR) ¹³ _(3-x) (OR¹⁴)_(x),where x is 0, 1, 2 or 3 and y is 0 or 1, R¹¹ and R¹³ are H or an alkylgroup containing from about 1 to 10 carbon atoms, a functionalized alkylgroup, an alkylene group, an aryl group, an alkylpolyether group andcombinations thereof, R10 and R14 are H, an alkyl group containing fromabout 1 to 10 carbon atoms, an acetyl group, and combinations thereof,wherein if y is 1 then R¹² can be an alkylene group containing fromabout 1 to 12 carbon atoms, an alkylenepolyether containing from about 1to 12 carbon atoms, an aryl group, an alkylene substituted aryl group,an alkylene group which may contain one or more olefins, or an oxygen orsulfur atom, and further wherein if x=0, then R¹¹ and R¹³ are a chlorineor bromine atom, and wherein the epoxy functional silane is present in amolar ratio to the disilane component and the metal oxide compositecolloid component of from about 0.1:1 to 4:1; and from about 0.1 toabout 70 weight percent, based on the total solids of theaqueous-organic solvent mixture, of an acidic colloidal silicacomponent, and wherein the amount of water present in theaqueous-organic solvent mixture is an amount sufficient to provide asubstantially homogenous mixture of hydrolysis products and partialcondensates of all reactive components.
 24. The article of claim 23wherein the aqueous-organic solvent mixture further comprises aneffective amount of co-hydrolysis catalyst to enhance the hydrolysisrates of the hydrolyzable components.
 25. The article of claim 24wherein the aqueous-organic solvent mixture further comprises aneffective amount of a catalyst thereby providing enhanced abrasionresistance to a cured coating.
 26. The article of claim 25 wherein theeffective amount of the catalyst is from about 0.01 to about 2 weightpercent, based on the total solids of the aqueous-organic solventmixture.
 27. The article of claim 26 wherein the aqueous-organic solventmixture further comprises an effective amount of a leveling agentthereby allowing the aqueous-organic solvent mixture to be spread on thesubstrate thereby providing substantially uniform contact of theaqueous-organic solvent mixture with the substrate.
 28. An articlehaving an abrasion resistant coating and a refractive index, the articlecomprising: a substrate; a coating composition applied to at least onesurface of the substrate and cured to provide the substrate with anabrasion resistant coating having a refractive index, the coatingcomposition comprising: an aqueous-organic solvent mixture containinghydrolysis products and partial condensates of an epoxy functionalsilane, a metal oxide composite colicid, a disilane, a carboxylic acidfunctional compound selected from the group consisting of monofunctionalcarboxylic acids, multifunctional carboxylic acids, anhydrides andcombinations thereof, wherein the disilane is represented by the formula(R¹⁰O)_(x)R¹¹ _(3-x)Si—R¹² _(y)—SiR¹³ _(3-x) (OR¹⁴)_(x), where x is 0,1, 2 or 3 and y is 0 or 1, R¹¹ and R¹³ are H or an alkyl groupcontaining from about 1 to 10 carbon atoms, a functionalized alkylgroup, an atkylene group, an aryl group, an alkylpolyether group andcombinations thereof, R10 and R14 are H, an alkyl group containing fromabout 1 to 10 carbon atoms, an acetyl group, and combinations thereof,wherein if y is 1 then R¹² can be an alkylene group containing fromabout 1 to 12 carbon atoms, an alkylenepolyether containing from about 1to 12 carbon atoms, an aryl group, an alkylene substituted aryl group,an alkylene group which may contain one or more olefins, or an oxygen orsulfur atom, and further wherein if x=0, then R¹¹ and R¹³ are a chlorineor bromine atom, and further wherein the epoxy functional silane ispresent in a molar ratio to the disilane component and the metal oxidecomposite colloid component of from about 0.1:1 to 4:1; and from about0.1 to about 70 weight percent, based on the total solids of thecomposition of a colloidal silica component, wherein the colloidalsilica component is acidic, basic or neutral.
 29. The article of claim28 wherein the colloidal silica component present in the aqueous-organicsolvent mixture is an acidic colloidal component.
 30. The article ofclaim 29 wherein the amount of water present in the aqueous-organicsolvent mixture is an amount sufficient to provide a substantiallyhomogeneous mixture of hydrolysis products and partial condensates ofall reactive components.
 31. The article of claim 30 wherein theaqueous-organic solvent mixture further corn praises an effective amountof co-hydrolysis catalyst thereby enhancing the hydrolysis rates of thehydrolyzable components.
 32. The article of claim 31 wherein theaqueous-organic solvent mixture further comprises an effective amount ofa catalyst for providing enhanced abrasion resistance to the curedcoating.
 33. The article of claim 32 wherein the effective amount of thecatalyst is from about 0.01 to about 2 weight percent, based on thetotal solids of the composition.
 34. An article having an abrasionresistant coating formed on at least one surface thereof, the abrasionresistant coating further having a refractive index, the abrasionresistive coating found by applying an aqueous-organic solvent mixtureto at least one surface of the article and thereafter curing theaqueous-organic solvent mixture to provide the abrasion resistantcoating, the aqueous-organic solvent mixture comprising: anaqueous-organic solvent mixture containing hydrolysis products andpartial condensates of an epoxy functional silane, a metal oxidecomposite colloid, a disilane, a carboxylic acid functional compoundselected from the group consisting of monofunctional carboxylic acids,multifunctional carboxylic acids, anhydrides and combinations thereof,and from about 0.1 to about 70 weight percent, based on the total solidsof the composition, of a mixture of hydrolysis products and partialcondensates of a silane additive represented by the formula R¹⁵_(x)Si(OR¹⁶)_(4-x) where x is an integer of 0, 1, 2 or 3, R¹⁵ is H, analkyl group containing from 1 to about 10 carbon atoms, a functionalizedalkyl group, an alkylene group, an aryl group an alkyl ether group andcombinations thereof, R¹⁶ is H, an alkyl group containing from 1 toabout 10 carbon atoms, an acetyl group and combinations thereof andwherein the disilane is represented by the formula (R¹⁰O)_(x)R¹¹_(3-x)Si—R¹² _(y)—SiR¹³ _(3-x) (OR¹⁴)_(x), where x is 0, 1, 2 or 3 and yis 0 or 1, R¹¹ and R¹³ are H or an alkyl group containing from about 1to 10 carbon atoms, a functionalized alkyl group, an alkylene group, anaryl group, an alkylpolyether group and combinations thereof, R10 andR14 are H, an alkyl group containing from about 1 to 10 carbon atoms, anacetyl group, and combinations thereof, wherein if y is 1 then R¹² canbe an alkylene group containing from about 1 to 12 carbon atoms, analkylenepolyether containing from about 1 to 12 carbon atoms, an arylgroup, an alkylene substituted aryl group, an alkylene group which maycontain one or more olefins, or an oxygen or sulfur atom, and furtherwherein if x=0, then R¹¹ and R¹³ are a chlorine or bromine atom, whereinthe epoxy functional silane is present in a molar ratio to the disilaneand the metal oxide composite colloid of from about 0.1:1 to 4:1; andfrom about 0.1 to about 70 weight percent, based on the total solids ofthe composition, of a colloidal silica component, and wherein thecolloidal silica component is acidic, basic or neutral.